OTTAWA - Justin Trudeau shook up the old boys' club on Parliament Hill on Wednesday, suspending two Liberal MPs amid allegations that they behaved inappropriately with two of their female New Democrat counterparts.

The Liberal leader booted Newfoundland MP Scott Andrews and Montreal MP Massimo Pacetti from his caucus and called for an independent investigation into accusations of what Trudeau termed "serious personal misconduct." He also suspended their candidacies for the next election, pending the outcome of the investigation.

The days when such incidents were dealt with quietly in parliamentary backrooms are long over, Trudeau told a news conference.

"Look, folks, it's 2014. It's time that this workplace, like other workplaces across the country, had a process whereby these issues can be aired and dealt with," he said.

"It is extremely important that we make it very clear that as an institution we will protect and encourage people who come forward with serious allegations of this type."

Both Andrews and Pacetti have denied the allegations. Nothing has been proven against them.

Nevertheless, Trudeau said he had a duty to take "fair but decisive" action after one of the NDP MPs "personally and directly" complained to him on Oct. 28. While he needs to be fair to all concerned, the "benefit of the doubt" must go to the complainants, given how difficult it is for them to come forward, he said.

Trudeau's swift action was also no doubt influenced by the scandal that has engulfed the CBC for the past two weeks over former radio star Jian Ghomeshi's alleged conduct with women. The public broadcaster has been criticized for not acting sooner to address Ghomeshi's alleged behaviour.

Neither the Liberals nor the NDP would reveal the names of the two complainants or even confirm publicly that they are New Democrats. However, NDP insiders said the two were shaken by Trudeau's decision to make the matter public and fear their names will inevitably leak out.

Insiders say Trudeau first learned of the allegations on Oct. 28 while attending the Hamilton funeral of Cpl. Nathan Cirillo, the soldier who was killed at the National War Memorial a week earlier by a gunman who later stormed Parliament Hill.

Trudeau said he immediately directed his party's whip, Judy Foote, to discuss the matter with her NDP counterpart, Nycole Turmel. Foote and Turmel met on Oct. 30 with the two complainants, who "confirmed the personal misconduct allegations."

On Wednesday, Foote apprised the Speaker of the House of Commons, Andrew Scheer, of the situation and suggested that a "neutral third party trusted by all concerned" be brought in to investigate.

She asked that the multi-party board of internal economy, which the Speaker chairs, urgently establish a process to investigate the allegations and similar complaints in future. While there is a procedure for Commons employees to lodge complaints, she said there's no similar process to deal with complaints between members of Parliament.

"Everyone who works in these places has a right to be in a secure work environment, free of harassment. We want to make sure that all parties work on these issues and I think that it's something that we should do together to show that it is something on which we all agree."

Andrews, MP for the riding of Avalon in Newfoundland and Labrador, was first elected in 2008 and re-elected in 2011. Until his suspension, he was the Liberal critic for access to information, privacy and ethics.

Pacetti, 52, is a veteran MP who was first elected to the Commons in a byelection in May 2002 in the Montreal riding of Saint-Leonard-Saint-Michel. He was re-elected in 2004, 2006, 2008 and 2011.

Both Andrews and Pacetti issued statements denying any wrongdoing and expressing confidence they'll be cleared by an investigation.

"I believe that our Parliament needs to be a workplace free of harassment, for both staff and MPs," Andrews said.

Dean Del Mastro reads his resignation statement in the House of Commons on Parliament Hill in Ottawa on Wednesday, Nov. 5, 2014.

OTTAWA - Disgraced Peterborough MP Dean Del Mastro abruptly resigned his House of Commons seat Wednesday, less than a week after a judge found him guilty on three counts of violating the Canada Elections Act.

Del Mastro, a former parliamentary secretary to Prime Minister Stephen Harper, was convicted of exceeding spending limits during the 2008 election, as well as failing to report a personal contribution of $21,000 to his own campaign and knowingly submitting a falsified document.

"I hope someday to be back in this place, but if I don't, always keep in mind it's a simple chair, but it represents the hopes and dreams and futures of thousands you represent and millions across the country," Del Mastro told the Commons, his voice quavering as he glanced back at his seat.

"Never take it for granted."

Del Mastro had many friends within his former Conservative caucus, many of whom were among the colleagues who applauded his speech when he was finished, along with several opposition members.

He made it clear he was stepping down in order to prevent embarrassment and division within the Conservative ranks. On Tuesday, MPs debated for three hours whether to suspend him without pay; the government and the NDP was prepared to do so, but the Liberals wanted him expelled immediately.

"To my colleagues in the Conservative party, I told a number of you I would never put you in a position where you'd have to vote on my future," he said.

"Stay united. I will not divide you, I will not be the one that divides you. I believe too much in what you do and what we stand for."

The Prime Minister's Office responded with a short statement. "We wish Mr. Del Mastro and his family well," spokesman Stephen Lecce said in an email.

Del Mastro is the fifth Conservative parliamentarian to resign or face suspension since the 2011 election. Last year, three former Conservative senators were suspended over contested living and housing expenses, while former cabinet minister Peter Penashue resigned last year over improper campaign contributions.

Del Mastro was expelled from the Conservative caucus on the day he was charged in September 2013, and had been sitting as an Independent.

Del Mastro, whose wife gave birth to their first child — a girl — on Sunday, has said his lawyer has asked a judge to re-open his defence in order to introduce new evidence before sentencing, which is scheduled for Nov. 21.

During Wednesday's 15-minute speech, Del Mastro continued to maintain his innocence. In 2008, his supporters didn't vote for him based on automatic phone calls telling them to do so, he argued — a service that was at the heart of his trial.

"I was built with a design flaw: I wasn't built with a reverse gear, I only know how to go forward," he said.

Del Mastro's seat is one of three that are currently open in the House of Commons.

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